RFR: 8286360: ARM32: Fix crashes after JDK-8284161 (Virtual Threads)

[Sergey Nazarkin]

On Fri, 3 Jun 2022 14:20:31 GMT, Dmitry Samersoff <dsamersoff at openjdk.org> wrote:

>> Virtual Threads are not fully implemented on ARM32, but there is a fallback implementation that can be used. Still, there is some VM code that is executed unconditionally anyway, crashing the VM on some tests. This improves the ARM32 code to the point that VM is able to build itself and pass tests. This adds the scaffolding for full implementation too.
>> 
>> Additional testing:
>>  - [x] Linux arm32 fastdebug build
>>  - [x] Linux arm32 fastdebug, `jdk_loom  hotspot_loom` pass
>
> src/hotspot/cpu/arm/frame_arm.inline.hpp line 47:
> 
>> 45: }
>> 46: 
>> 47: inline frame::frame(intptr_t* sp) {
> 
> Will AArch64 code work?
> 
> inline frame::frame(intptr_t* sp) : frame(sp, sp, *(intptr_t**)(sp - frame::sender_sp_offset), *(address*)(sp - 1)) {}

This function seems abandoned and candidate for deletion in the  future.

-------------

PR: https://git.openjdk.java.net/jdk/pull/8634